Flasks, in particular retractable feeding bottles

ABSTRACT

A flask having a retractable body of approximately cylindrical plastic material formed by a succession of conical upper and lower sections connected at their apexes and in their troughs, an angle α being formed between the conical upper section and a transverse plane and an angle β being formed between the conical lower section and a transverse plane, wherein the succession of conical sections alternate rigid/flexible, making it possible to obtain at least two stable extension positions, and a plurality of stable intermediate positions having axial symmetry, and wherein the radius of curvature of the troughs is less than or equal to about 0.2 millimeters.

RELATED APPLICATION

[0001] This is a continuation of International Application No.PCT/FR99/01496, with an international filing date of Jun. 22, 1999,which is based on French Patent Application No. 98/08193, filed Jun. 22,1998, French Patent Application No. 98/08420, filed Jul. 1, 1998, andFrench Patent Application No. 98/15945, filed Dec. 17, 1998.

FIELD OF THE INVENTION

[0002] This invention concerns flasks, in particular feeding bottles.More particularly, this invention relates to retractable feedingbottles, the height of which may be reduced outside periods of use.

BACKGROUND

[0003] In the state of the art, different versions of flasks orretractable bottles have been proposed.

[0004] FR 2467146 discloses in particular semi-rigid packagingconstituted by a ringed sleeve the corrugations of which, with anessentially triangular shaped cross-section, allow stable contraction bytilting a part at least of them beyond a position of equilibrium so thateach of the corrugations has a stable position in the compressed stateor in the deployed state. The sleeve delimits an inner volume which canvary in a substantial ratio between extreme states where all thecorrugations are compressed or deployed.

[0005] U.S. Pat. No. 5,348,173 discloses embodiment details of suchretractable packaging.

[0006] Also known are U.S. Pat. No. 2,780,378, U.S. Pat. No. 3,143,429,GB 2181062 and EP 300786 concerning compressible containers also havingthe general shape of bellows. Indeed, prior art products retaincompression memory: when the feeding bottle is decompressed after a longperiod of being kept in the compressed position, it does not regain itsnominal capacity.

[0007] These types of packaging have defects, however. They do notguarantee the capacity in the deployed position. Indeed, significantvariations may occur when the prior art packaging is subject to multipleextension and retraction manipulations.

[0008] On the other hand, prior art devices do not guarantee harmoniousand regular compression or deployment of the bellows, and often do notguarantee the stability of the extreme and intermediate positions.

[0009] These drawbacks make the prior art device unsuitable for someapplications, particularly for the manufacture of a feeding bottle.

[0010] Indeed, for such applications, certain characteristics arerequired. It is desirable for the capacity of the feeding bottle in thedeployed position to be constant and reproducible, to allow a precisedosage of the content by means of lateral calibration marks.

[0011] Prior art devices do not allow such consistency of capacity to beguaranteed, and the lateral marks which could be affixed to the wallwould not allow the volume of liquid introduced into the packaging to bededuced. Moreover, it will be noted that the prior art does not suggestusing such calibration marks.

[0012] Secondly, a feeding bottle must be sufficiently stable, in thedeployed position, to prevent unexpected axial pressure from causing anuntimely compression. Such a compression would have very prejudicialeffects, creating excess pressure of the contents, a liquid overflow,and a risk of choking the baby by excess of liquid delivered by thefeeding bottle.

[0013] Finally, it may be desirable for the capacity of the feedingbottle to be able to be periodically adjusted to expel the air, toreduce the risks of absorption of air by the baby. The absorption ofexcessive air causes risks of aerophagia finding expression, for thebaby, in abdominal pains. For this reason it must allow compression intostable intermediate positions.

[0014] Furthermore, the bellows shape in the retracted or partiallycompressed position must allow a liquid flow without the formation ofareas of stagnation of the liquid contained in the container.

[0015] Thus, it would be highly advantageous to improve prior artbellows packaging to overcome these drawbacks.

SUMMARY OF THE INVENTION

[0016] The invention relates to a flask having a retractable body ofapproximately cylindrical plastic material formed by a succession ofconical upper and lower sections connected at their apexes and in theirtroughs, an angle α being formed between the conical upper section and atransverse plane and an angle β being formed between the conical lowersection and a transverse plane, wherein the succession of conicalsections alternate rigid/flexible, making it possible to obtain at leasttwo stable extension positions, and a plurality of stable intermediatepositions having axial symmetry, and wherein the radius of curvature ofthe troughs is less than or equal to about 0.2 millimeters.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention will be better understood from reading thefollowing description of an embodiment example, with reference to theappended drawings wherein:

[0018]FIGS. 1 and 2 show cross-section views of an embodiment detail ofa feeding bottle, in the decompressed and compressed positions,respectively.

[0019]FIGS. 3 and 4 show cross-section view of the feeding bottle.

[0020]FIGS. 5 and 6 show views of details of the feeding bottle body.

DETAILED DESCRIPTION

[0021] The following description is intended to refer to specificembodiments of the invention illustrated in the drawings and is notintended to define or limit the invention, other than in the appendedclaims. Also, the drawings are not to scale and various dimensions andproportions are contemplated.

[0022] The invention concerns a flask, in particular a feeding bottle,having a retractable body of approximately cylindrical plastic material,characterized in that the body is constituted by a succession ofconical, alternate rigid/flexible sections making it possible to obtainat least two stable extension positions, and a plurality of stableintermediate positions having axial symmetry, and in that the angle α isgreater than the angle β, wherein

[0023] α denotes the angle formed between the upper edge and atransverse plane and

[0024] β denotes the angle formed between the lower edge and atransverse plane.

[0025] Preferably, α-β is greater than or equal to about 4°. To thisend, the upper edge is thicker and, therefore, more rigid than the loweredge, which is thereby more flexible than the upper edge.

[0026] Advantageously, the radius of curvature of the connection zonebetween the conical upper wall and the conical lower wall is greaterthan or equal to twice the thickness of the wall. The angle β formedbetween the transverse plane and the conical lower wall is between about35° and about 40°.

[0027] According to one particular variant, the ratio I/R between thelength I of the lower edge and the radius R at the trough is betweenabout 0.35 and about 0.50.

[0028] According to another variant, the bottom has a ring to exerttraction on the body of the feeding bottle. Advantageously, the ratiobetween the generators S and I of two consecutive conical sectors isabout 1.25.

[0029] According to an advantageous embodiment, the flash according tothe invention has on its wall calibration marks for determining thevolume of liquid contained in the bottle in the deployed position.

[0030] The feeding bottle body according to the invention, shown in theappended figures, is constituted by a succession of conical sections (1to 2) connected, when the feeding bottle is in the deployed position, inthe shape of lenses to form a corrugated hollow body. These conicalupper (1) and lower (2) sections are connected at their apexes (100) andin their troughs (200).

[0031] When the feeding bottle is compressed as shown in FIG. 2, theconical lower section (1) is folded back under the conical upper section(2). The conical lower section (2) tilts relative to the transversemedian plane (300). The lower section (2) is above the transverse plane(300) passing through the trough (200) of a lenticular segment (400)when the feeding bottle is deployed. It is beneath the transverse plane(300) when the feeding bottle is compressed.

[0032] The feeding bottle will be described below as a non-restrictiveexample, for a maximum capacity (corresponding to the deployed position)of the container of 305 milliliters, for a height of 147.4 mm and amaximum cross-section of 64 mm.

[0033] The body includes a plurality of lenticular elements (3 to 10)formed by the affixing of two conical sections (1,2) as shown in FIG. 3.

[0034] The connection between two lenticular elements, at trough level,has a radius of curvature close to 0, in any case lower than or equal toabout 0.2 millimeters. The thickness is an element which may upsetcomponent operation, compression and decompression and the maintenanceof the spiral track in the compressed position, it can even preventcompression if it is substantial.

[0035] 1—Influence of the optimum distribution of thicknesses on thegeometry.

[0036] 2—Influence of the rigidity of the material: Young's modulus oncompression and decompression stresses.

[0037] The compression and jointing condition of a spiral track atthickness level without mentioning compression energy but onlyfeasibility is expressed by a trough radius in the vicinity of 0 to 0.2millimeters. The trough is an intersection of the thickness of the loweredge and upper edge.

[0038] At this point contrary to the apex, the material expands less onaccount of its proximity to the center.

[0039] To create the jointing, it is necessary to break the accumulationof materials at this point so that the spiral track compresses and stayscompressed.

[0040] The mechanisms engaged during compression of the feeding bottleare as follows:

[0041] Two buckling mode types may appear:

[0042] 1. The first mode is a mode accompanied by large displacementswhich leads to a sharp increase in the rigidity of the component (FIG.5).

[0043] 2. The second is a more local mode accompanied by much smallerdisplacements localized on the edges of the spiral tracks. Theappearance of this second mode does not induce any appreciable increasein rigidity (FIG. 6).

[0044] A non homogenous distribution of the thicknesses (thicknesses atthe apexes, troughs and edges of different spiral tracks according tothe spiral tracks) favors the appearance of the first buckling mode. Thedirect consequence of homogenizing the thicknesses is a reduction in theenergy required for compression.

[0045] Reducing the thickness in the troughs of spiral tracks and at theapexes allows a substantial gain in compression energies. But in bothcases, the reductions in thickness do not make it possible to havebetter control of the buckling mode appearance and type shown in FIGS. 5and 6.

[0046] Introducing a more substantial thickness on the upper edges thanon the lower edges of the spiral tracks makes it possible on the onehand to control more effectively and to anticipate the appearance offirst mode types by increasing the rigidity of the upper edges, on theother hand to create preferential flexion areas on the lower edges. Thisdesign, therefore, allows a consequent gain in the energy necessary forcompressing the feeding bottle.

[0047] Decompression does not lead to the buckling mode appearance butthe previous conclusions remain true. A more homogenous distribution ofthicknesses makes it possible to reduce energy in decompression, thehinge effect at the apexes is more pronounced than that in the troughs,the creation of thicker and, therefore, more rigid areas on the upperedges and correlatively that of preferential flexion areas on the loweredges makes it possible to reduce the energy required for decompression.

[0048] Reducing the Young's modulus of the material does not bringconsequent gains relative to those stemming from an optimizeddistribution of thicknesses. Reducing the modulus, if it leads to lowercompression energies, leads also to more flexible components thestability, particularly lateral, of which in operation may be muchreduced.

[0049] A better distribution of thicknesses and possibly a material of aYoung's modulus of less than about 950 Mpa, (800 and 650 Mpa) makes itpossible tor educe (almost 100%) the energy necessary for decompressingand compressing the feeding bottle. It must be noted that for anidentical effort, the decompression energy is overall equivalent to thecompression energy but that the observations made above make it possibleto decompress the feeding bottle with low intensity efforts which do notallow compression. The feeding bottle may, therefore, overall bedecompressed with less effort than that required to compress it.

[0050] The lower lenticular element (3) includes a lower element theexternal cross-section of which is 64 mm and the height 5.4 mm, and anconical upper element the generator of which is 13.0 mm, and forms withthe vertical an angle of 28.5°. The total height of this firstlenticular element (3) is 17.7 mm.

[0051] As shown in FIG. 4, the following lenticular element (4) has aheight of 16.9 mm. The conical lower sector has a length of 8.9 mm andforms with the vertical an angle of 39°. The conical upper sector has alength of 10.5 mm, and forms with the vertical an angle of 44°.

[0052] The five following lenticular elements (5 to 9) are formed by aconical lower sector the generator of which has a length of 10.2 mm andforms with the vertical an angle β of 40°, and of an conical uppersector the generator of which has a length of 12 mm and forms with thevertical an angle α of 47°.

[0053] To avoid the effects of hysteresis, it is necessary to respect acertain geometry of the edges between themselves. The dimensions andangles are denoted in references in FIG. 3.

[0054] Dimension of the Lower edge=I

[0055] Dimension of the Upper edge=S

[0056] R—Radius from the trough to the center, on the transverse plane.

[0057] α is the angle formed between the upper edge and the transverseplane.

[0058] β is the angle formed between the lower edge and the transverseplane.

[0059] For the feeding bottle according to the invention, the followingformulas are maintained:

[0060] α>β.

[0061] α being the angle of the upper edge, β that of the lower edgewhich buckles.

[0062] I/R must be between 35% and 50%.

[0063] In the example described,

[0064] I=8.9 mm.

[0065] R=25 mm. The ratio is 35.6%.

[0066] α must be greater than β by at least about 4°. This valueincludes the possible thickness of the lower edge. Ideally, β must bebetween about 35° and about 40°. Beyond about 40°, it becomes difficultto compress it.

[0067] α must be greater by at least about 4° relative to β since afterkinematics, the lower edge β will be positioned at β′. If β′ stopsagainst the upper edge at β′-α, the lower edge does not compress but isdeformed and may rebound. If the dimensions are respected furthermore,alpha must be larger but must not exceed about 20%.

[0068] According to an embodiment example,

[0069] α=44°

[0070] β=39% (β=88% of α)

[0071] The closer the angle β to the straight line which starts from theapexes, the easier the compression. The concept of retractable flasksthe height of which may be reduced outside periods of use is appliedhere for disposable feeding bottles characterized by a spiral geometry.

[0072] The feeding bottle is sold sterile and compressed. It must,therefore, be decompressed to be used. After use, the feeding bottle iscompressed to be disposed of. In every case, the user must be able todecompress and compress the feeding bottle easily. On the other hand,he/she must be able to use it without there being a risk of compressionduring use. For such feeding bottles, the compression and decompressionphases must be able to be carried out with minimum effort nonethelessguaranteeing stability during use.

[0073] The “Passage Point” “stress”

[0074] To ensure that the lower edge buckles before the upper edgebuckles, and to avoid hysteresis events, it is necessary to optimize thestress of the edges.

[0075] In compression:

[0076] Lower: The projection of the lower edge towards a virtual pointlocated on the horizontal starting from the apexes, represents with theradius of this same edge on the horizontal, the value of the stress.

[0077] The stress of β must not exceed about 22%+− about 1% of thedimension of the lower edge.

[0078] The stress of β must be between about 21 and about 23% of I(dimension of the lower edge).

[0079] The stress of α must be greater than that of β. If the reverseoccurs, it is the upper edge which will tend to deform first. In orderthat only the lower edge compresses, it is necessary to ensure that thestress of the upper edge is greater than that of the lower edge.

[0080] Nonetheless the gap between the two stresses must be reduced. Tothis end, the stress β would have to be greater than or equal to about60% of the stress of α. Below about 60% a high energy deployment problemis encountered. A stress of β=47% of the stress of α translates, forexample, into an excessively hard manipulation.

[0081] e.g.: Upper stress 2.9 mm

[0082] Lower stress 2.0 mm

[0083] Furthermore, when the stress of β is greater than about 70% ofthe stress of α, the bellows has a shape memory producing the effect ofhysteresis. The closer the angle β to the straight line which startsfrom the apexes, the easier the compression on account of the fact thatthe stress of the lower edge is closer to its projection and, therefore,the stress is closer to 0. This condition is obtained with an angle ofabout 25° and below. But with this value, retention of liquid in thespiral tracks may be observed. Reliability and reproducibility ofcapacity is, therefore, lost.

[0084] To improve compaction or miniaturization of the feeding bottle,the lower edge must represent in dimension at least about 80% of thedimension of the upper edge.

[0085] The lower edge may, therefore, be from about 80% to about 100% ofthe dimension of the upper edge. If this value is exceeded, the feedingbottle becomes, after compression, an upturned conical component. Thisvalue is preferably between about 80% and about 95%.

[0086] The feeding bottle is made up of spiral tracks each representingan effective volume of 30 ml. The upper lenticular element (10) isextended by a threaded cylindrical part (11). The total height of thecorrugated part is 127.6 mm in the deployed position. It has volumecalibrated calibration marks (12). Retractability is obtainedpreferentially by pressures along alternate oblique axes, and not alongone axial direction.

[0087] A pressure movement is exerted with lateral dissymmetry to forcetilting of one side of a lenticular element, then a second pressure isexerted with an opposite lateral component to complete the compressionof this first lenticular element.

[0088] This alternate movement is then continued until the compressionis obtained of the requisite number of lenticular elements. The feedingbottle then remains in a stable intermediate position.

[0089] The material selected is here polypropylene with a modulus ofabout 950 Mpa for its greater resistance to heat, necessary when heatingthe feeding bottle and for its transparency making it possible to seethe formation of lumps from powdered milk, and lastly for its rigiditynecessary for the proper handling and stability of the feeding bottle.

What is claimed is:
 1. A flask having a retractable body ofapproximately cylindrical plastic material formed by a succession ofconical upper and lower sections connected at respective apexes andtroughs, an angle α being formed between the conical upper section and atransverse plane and an angle β being formed between the conical lowersection and a transverse plane, wherein the succession of conicalsections alternate rigid/flexible, to thereby obtain at least two stableextension positions, and a plurality of stable intermediate positionshaving axial symmetry, and wherein the radius of curvature of thetroughs is less than or equal to about 0.2 millimeters.
 2. The flaskaccording to claim 1 , wherein the angle α is greater than the angle β.3. The flask according to claim 1 , wherein α-β is greater than or equalto about 4°.
 4. The flask according to claim 2 , wherein α-β is greaterthan or equal to about 4°.
 5. The flask according to claim 1 , whereinthe radius of curvature of a connection zone between conical uppersection and conical lower section is greater than or equal to twice thethickness of the wall.
 6. A flask according to claim 1 , wherein theangle β formed between is about 35° and about 40°.
 7. The flaskaccording to claim 1 , wherein a ratio I/R between length I of the lowersection and radius R at a trough is between about 0.35 and about 0.50.8. The flask according to claim 1 , further comprising wall calibrationmarks for determining the volume of liquid contained in the flask in anexpanded mode.
 9. The flask according to claim 1 , wherein the length ofthe lower section is greater than about 80% of the dimension of theupper section.
 10. The flask according to claim 1 , wherein stress β isgreater than or equal to about 60% of stress α.
 11. The flask accordingto claim 1 , wherein stress β is less than or equal to about 80% ofstress of α.
 12. The flask according to claim 1 , wherein the uppersections are thicker than the lower sections.